Adequate blood supply is critical to tissue repair and regeneration and is frequently lacking in disease or injury. Therefore, agents that stimulate improved blood supply may be useful in a wide variety of health conditions. A fundamental pathway engaged in response to oxygen and nutrient deficit is the hypoxia inducible factor (HIF) pathway. Under normoxia, HIF molecules are constitutively degraded by oxygen dependent prolyl hydroxylase enzymes. Exposure to hypoxia inhibits prolyl hydroxylation which causes HIF to accumulate in the nucleus where it transactivates hypoxic responsive genes. There has been substantial interest in manipulating the HIF pathway both to impair and induce angiogenesis. Although several HIF activating agents have been identified, additional compounds are needed as there are drawbacks associated with current agents including toxicity and high costs. In this proposal, we seek to access the Molecular Library Screening Centers Network resources to screen for compounds which activate HIF. A high throughput assay will be used in which a cell line has been stably transfected with a luciferase reporter driven by HREs. It is anticipated that the screen may identify novel molecular probes which may reveal additional mechanisms of HIF activation. Ultimately, the development of techniques to improve tissue survival during ischemia and improve angiogenesis could have a broad scope of clinical application. PUBLIC HEALTH RELEVANCE: Many disease processes and injuries have in common poor blood supply and/or lack of oxygen. The current proposal seeks to find agents that can activate the hypoxia inducible factor pathway which is responsible for initiating a response to low oxygen that includes metabolic adaptation and development of increased blood supply. These activators of the HIF pathway may be useful in a broad range of diseases such as heart disease and limb ischemia and in approaches to tissue regeneration. [unreadable] [unreadable] [unreadable]